diff --git a/packages/next-polyfill-nomodule/src/index.js b/packages/next-polyfill-nomodule/src/index.js
index 6d2a5e38dcb45a66b2329ad4ee25b99d9987ecff..51f97f54997fd250b3eef623b72a32fab78c7498 100644
--- a/packages/next-polyfill-nomodule/src/index.js
+++ b/packages/next-polyfill-nomodule/src/index.js
@@ -3,6 +3,7 @@ import 'core-js/features/array/fill'
 import 'core-js/features/array/find'
 import 'core-js/features/array/find-index'
 import 'core-js/features/array/flat-map'
+import 'core-js/features/array/flat'
 import 'core-js/features/array/from'
 import 'core-js/features/array/includes'
 import 'core-js/features/array/iterator'